This is shown because The -d switch runs the container in the background, otherwise the web server’s standard input/output streams would be attached to our development machine’s shell. So I have removed it.
As I have seen this already in dnxcore50 vs dnx451, I know that real case is that my project enfroces usage of dnxcore50, so coreclr. On docker it’s running on wrong target framework.

"frameworks": {
"dnxcore50": {
"dependencies": {
}
}

And I have done it by purpose, I don’t want to use mono and now I want to have docker with coreclr.
Solution is to modify Dockerfile to use proper image and up to date kestrel command.